In electronics a NOT gate is more commonly called an inverter. The circle on the symbol is called a bubble, and is used in logic diagrams to indicate a logic negation between the external logic state and the internal logic state (1 to 0 or vice versa).
A weather watch, on the other hand, typically refers to an alert issued to indicate that conditions are favorable for the development of dangerous weather patterns, although the dangerous weather conditions themselves are not currently present.
Best Answer: A tornado watch (sometimes referred to as a red box by meteorologists and storm chasers) is issued when weather conditions are favorable for the development of tornadoes in and close to the watch area.